259356

Appears in sequences

• Convolution of Catalan numbers A000108 with A020918.at n=6A045724
• Triangle related to A001700 and A000302 (powers of 4).at n=48A046658
• a(n) = Sum_{k=0..n} binomial(3*n+1,k) * binomial(2*n-k-1,n-k).at n=6A386937